A father who lost his entire family in a house fire has issued a fresh appeal for witnesses to help him understand the tragedy, as police revealed the property was burgled on the night of the blaze.

Dr Abdul Shakoor's wife Dr Sabah Usmani, sons Sohaib, 11, and Rayyan, six, and daughter Hira, 13, died in the blaze at Barn Mead, Harlow, Essex. A third son, Muneeb, nine, and a second daughter, Maheen, three, died later in hospital.

Essex Police have now said they believe there was a burglary at the property on the night of the fire after the family had gone to bed and before the blaze was discovered.

Investigators originally suspected the fire on October 15 was an arson attack but no accelerant has so far been found at the scene.

Dr Shakoor, the tragedy's sole survivor, read a statement imploring anyone with information to help provide answers to the questions that remain.

Unable to fight back tears, he said: "I do not understand why my little children who were so happy and full of life, who had so much to live for, are no longer here.

"I ask from my heart that anyone with information comes forward to help, so that I may understand the tragedy that has so befallen my beautiful family. Even a small piece of information may make a difference and, however difficult it may be, I ask anyone who knows what happened to do the right thing, to come forward and to talk to the police."

Detective Superintendent Rob Vinson, the senior investigating officer on the case, said police believe several items including a laptop were removed from the house on the night of the fire.

He said: "Our inquiries have revealed that in Harlow during the same evening and early morning there were two other unsuccessful attempts to break into other properties and one where entry was gained but the suspect was disturbed and nothing was taken. How these incidents relate to the current investigation is ongoing."

Det Supt Vinson said he was keen to speak to a teenage boy of around 15 or 16 and a slim girl in a school uniform who were seen throwing Dr Shakoor's laptop bag away near garages in Whitewaits, Harlow. The bag was found on October 26 containing personal papers and a laptop lead. A spokesman for Essex Police said later that the schoolgirl and teenage boy seen throwing away the laptop bag had come forward and were speaking to detectives.